Add layer1 over IP support

Implement a ISDN over IP tunnel to use mISDN hardware on
remote locations.

Signed-off-by: Karsten Keil <kkeil@suse.de>

drivers/isdn/mISDN/Kconfig

@@ -23,5 +23,22 @@ config MISDN_DSP
 	  and get more informations about this module and it's usage.
 	  If unsure, say 'N'.
 
-	source "drivers/isdn/hardware/mISDN/Kconfig"
+config MISDN_L1OIP
+	tristate "ISDN over IP tunnel"
+	depends on MISDN
+	help
+	  Enable support for ISDN over IP tunnel.
+
+	  It features:
+	    - dynamic IP exchange, if one or both peers have dynamic IPs
+	    - BRI (S0) and PRI (S2M) interface
+	    - layer 1 control via network keepalive frames
+	    - direct tunneling of physical interface via IP
+
+	  NOTE: This protocol is called 'Layer 1 over IP' and is not
+	  compatible with ISDNoIP (Agfeo) or TDMoIP. Protocol description is
+	  provided in the source code.
+
+source "drivers/isdn/hardware/mISDN/Kconfig"
+
 endif #MISDN

drivers/isdn/mISDN/Makefile

@@ -4,8 +4,10 @@
 
 obj-$(CONFIG_MISDN) += mISDN_core.o
 obj-$(CONFIG_MISDN_DSP) += mISDN_dsp.o
+obj-$(CONFIG_MISDN_L1OIP) += l1oip.o
 
 # multi objects
 
 mISDN_core-objs := core.o fsm.o socket.o hwchannel.o stack.o layer1.o layer2.o tei.o timerdev.o
 mISDN_dsp-objs := dsp_core.o dsp_cmx.o dsp_tones.o dsp_dtmf.o dsp_audio.o dsp_blowfish.o dsp_pipeline.o dsp_hwec.o
+l1oip-objs := l1oip_core.o l1oip_codec.o

drivers/isdn/mISDN/l1oip.h

@@ -0,0 +1,91 @@
+/*
+ * see notice in l1oip.c
+ */
+
+/* debugging */
+#define DEBUG_L1OIP_INIT	0x00010000
+#define DEBUG_L1OIP_SOCKET	0x00020000
+#define DEBUG_L1OIP_MGR		0x00040000
+#define DEBUG_L1OIP_MSG		0x00080000
+
+/* enable to disorder received bchannels by sequence 2143658798... */
+/*
+#define REORDER_DEBUG
+*/
+
+/* frames */
+#define L1OIP_MAX_LEN		2048		/* max packet size form l2 */
+#define L1OIP_MAX_PERFRAME	1400		/* max data size in one frame */
+
+
+/* timers */
+#define L1OIP_KEEPALIVE		15
+#define L1OIP_TIMEOUT		65
+
+
+/* socket */
+#define L1OIP_DEFAULTPORT	931
+
+
+/* channel structure */
+struct l1oip_chan {
+	struct dchannel       	*dch;
+	struct bchannel       	*bch;
+	u32			tx_counter;	/* counts xmit bytes/packets */
+	u32			rx_counter;	/* counts recv bytes/packets */
+	u32			codecstate;	/* used by codec to save data */
+#ifdef REORDER_DEBUG
+	int			disorder_flag;
+	struct sk_buff		*disorder_skb;
+	u32			disorder_cnt;
+#endif
+};
+
+
+/* card structure */
+struct l1oip {
+	struct list_head        list;
+
+	/* card */
+	int			registered;	/* if registered with mISDN */
+	char			name[MISDN_MAX_IDLEN];
+	int			idx;		/* card index */
+	int			pri;		/* 1=pri, 0=bri */
+	int			d_idx;		/* current dchannel number */
+	int			b_num;		/* number of bchannels */
+	u32			id;		/* id of connection */
+	int			ondemand;	/* if transmis. is on demand */
+	int			bundle;		/* bundle channels in one frm */
+	int			codec;		/* codec to use for transmis. */
+	int			limit;		/* limit number of bchannels */
+
+	/* timer */
+	struct timer_list 	keep_tl;
+	struct timer_list 	timeout_tl;
+	int			timeout_on;
+	struct work_struct	workq;
+
+	/* socket */
+	struct socket 		*socket;	/* if set, socket is created */
+	struct completion 	socket_complete;/* completion of sock thread */
+	struct task_struct	*socket_thread;
+	spinlock_t 		socket_lock;	/* access sock outside thread */
+	u32			remoteip;	/* if all set, ip is assigned */
+	u16	 		localport;	/* must always be set */
+	u16	 		remoteport;	/* must always be set */
+	struct sockaddr_in	sin_local;	/* local socket name */
+	struct sockaddr_in	sin_remote;	/* remote socket name */
+	struct msghdr		sendmsg;	/* ip message to send */
+	struct iovec		sendiov;	/* iov for message */
+
+	/* frame */
+	struct l1oip_chan	chan[128];	/* channel instances */
+};
+
+extern int l1oip_law_to_4bit(u8 *data, int len, u8 *result, u32 *state);
+extern int l1oip_4bit_to_law(u8 *data, int len, u8 *result);
+extern int l1oip_alaw_to_ulaw(u8 *data, int len, u8 *result);
+extern int l1oip_ulaw_to_alaw(u8 *data, int len, u8 *result);
+extern void l1oip_4bit_free(void);
+extern int l1oip_4bit_alloc(int ulaw);
+